A precise coupling-in or coupling-out the light or the radiation into the waveguide is necessary for the optical connection of an optoelectronic semiconductor component to a waveguide on a substrate carrier. Optical coupling systems which transmit the radiation from one component onto another one are used for this, wherein such optical coupling systems are applied for example in the field of optoelectronics, in particular in optical communication, in computing and in optical sensor systems. In particular, optical and optoelectronic components such as for example photo-detectors, semiconductor lasers, in particular surface emitters (VCSEL vertical cavity surface emitter laser) as well as semiconductor-based integrated optoelectronic circuits are considered as semiconductor components. The mentioned radiation, which is also indicated as light, light beams, a light signal or a light impulse, is typically monochromatic or usually has wavelengths within a narrow wavelength range.
Typically, light beams, at least in sections are led in light waveguides, wherein the light waveguides are often arranged on surfaces of two-dimensional substrates or carriers. With such “planarly integrated” light waveguides, there is often the problem of transmitting the light beams from the light waveguide perpendicularly or at a predefined angle to the surface of the substrate or carrier, onto another component, specifically onto an optoelectronic component, or of coupling a light beam coming from the component in the reverse direction perpendicularly or at a predefined angle to the surface of the substrate or carrier, into the light waveguide.
For this purpose, the radiation is often deflected at a mirror surface which is integrated in the carrier, wherein the mirror surface is to be aligned at a 45° angle to the surface of the substrate, in order to permit a perpendicular coupling-out or coupling-in of the light beam. For this, it is for example known to grind the substrate from the lower side at a 45° angle or to machine it with a laser. It is also known to emboss a 45° plane into a polymer substrate and to subsequently metallise this plane. Other mirrors which are produced in a standard silicon wafer by way of micromechanical technologies, for example have angles between 40° and 60° to the substrate surface, which leads to a beam deflection, by way of which the exiting radiation deviates from the perpendicular.
Moreover, so-called grating couplers are known, with which the coupling structures are Bragg gratings which are etched into waveguides, e.g. of silicon. The coupling efficiency is thereby dependent on the angle and optical coupling angles which differ from the perpendicular are defined for an optimal coupling-in or coupling-out of the light into or out of the optical waveguides.